Question

Giải các phương trình :

a) \(7+2x=22-3x\)

b) \(8x-3=5x+12\)

c) \(x-12+4x=25+2x-1\)

d) \(x+2x+3x-19=3x+5\)

e) \(7-\left(2x+4\right)=-\left(x+4\right)\)

f) \(\left(x-1\right)-\left(2x-1\right)=9-x\)

Answer 1

a)X= 3 b)X= 5 c)X= 12

d)X= 8 e)X= 7 f)X= ?

Answer 2

Answer 3

a) 7 + 2x = 22 – 3x⇔ 2x + 3x = 22 – 7⇔ 5x = 15⇔ x = 3

b) 8x – 3 = 5x + 12⇔ 8x – 5x = 12 + 3⇔ 3x = 15⇔ x = 5

c) x – 12 + 4x = 25 + 2x -1⇔x + 4x – 2x = 25 -1 + 12⇔ 3x = 36⇔ x = 12

d) x + 2x + 3x- 19 = 3x + 5⇔ x + 2x + 3x – 3x = 19 + 5⇔ 3x = 24⇔ x = 8

e) 7 – (2x = 4) = -(x+4)⇔ 7 – 2x – 4 = -x – 4 -2x + x = 4 – 7 – 4⇔ -x = -7⇔ x = 7

f) (x – 1) – (2x – 1) = 9 – x⇔ x – 1 – 2x + 1 = 9 – x⇔ x – 2x + x = 9 + 1 – 1⇔ 0x = 9<-->Phương trình vô nghiệm

Answer 4

a)7+2x=22-3x

⇔2x+3x=22-7

⇔5x=15⇔x=3

b)8x-3=5x+12

⇔8x-5x=12+3

⇔3x=15⇔x=5

c)x-12+4x=25+2x-1

⇔x+4x-2x=25-1+12

⇔3x=36⇔x=12

Answer 5

d)x+2x+3x-19=3x+5⇔x+2x+3x-3x=5+19⇔3x=24⇔x=8

e)7-(2x+4)=-(x+4)⇔7-2x-4=-x-4⇔-2x+x=-4-7+4⇔-x=-7⇔x=7

f)(x-1)-(2x-1)=9-x⇔x-1-2x+1=9-x⇔x-2x+x=9+1-1⇔0x=9